CEO Turnover, Equity-Based Compensation And Firms Investment Decisions

This paper examines the impact of the newly appointed CEOs on firms future investment decisions and whether the relation is affected by the equity-based compensation, corporate governance provisions and other CEO characteristics. Using CEO turnover data from 1992-2004, the results show that new CEOs with high options-based compensation, following forced turnover and with shorter organization tenure, are associated with high R&D and advertisement investments. These results are consistent with the managerial incentive effect and the dismissal effect

Annotating Protein Functional Residues by Coupling High-Throughput Fitness Profile and Homologous-Structure Analysis.

Identification and annotation of functional residues are fundamental questions in protein sequence analysis. Sequence and structure conservation provides valuable information to tackle these questions. It is, however, limited by the incomplete sampling of sequence space in natural evolution. Moreover, proteins often have multiple functions, with overlapping sequences that present challenges to accurate annotation of the exact functions of individual residues by conservation-based methods. Using the influenza A virus PB1 protein as an example, we developed a method to systematically identify and annotate functional residues. We used saturation mutagenesis and high-throughput sequencing to measure the replication capacity of single nucleotide mutations across the entire PB1 protein. After predicting protein stability upon mutations, we identified functional PB1 residues that are essential for viral replication. To further annotate the functional residues important to the canonical or noncanonical functions of viral RNA-dependent RNA polymerase (vRdRp), we performed a homologous-structure analysis with 16 different vRdRp structures. We achieved high sensitivity in annotating the known canonical polymerase functional residues. Moreover, we identified a cluster of noncanonical functional residues located in the loop region of the PB1 β-ribbon. We further demonstrated that these residues were important for PB1 protein nuclear import through the interaction with Ran-binding protein 5. In summary, we developed a systematic and sensitive method to identify and annotate functional residues that are not restrained by sequence conservation. Importantly, this method is generally applicable to other proteins about which homologous-structure information is available.ImportanceTo fully comprehend the diverse functions of a protein, it is essential to understand the functionality of individual residues. Current methods are highly dependent on evolutionary sequence conservation, which is usually limited by sampling size. Sequence conservation-based methods are further confounded by structural constraints and multifunctionality of proteins. Here we present a method that can systematically identify and annotate functional residues of a given protein. We used a high-throughput functional profiling platform to identify essential residues. Coupling it with homologous-structure comparison, we were able to annotate multiple functions of proteins. We demonstrated the method with the PB1 protein of influenza A virus and identified novel functional residues in addition to its canonical function as an RNA-dependent RNA polymerase. Not limited to virology, this method is generally applicable to other proteins that can be functionally selected and about which homologous-structure information is available

Multiferroic and Ferroic Topological Order in Ligand-Functionalized Germanene and Arsenene

Two-dimensional (2D) materials that exhibit ferroelectric, ferromagnetic, or topological order have been a major focal topic of nanomaterials research in recent years. The latest efforts in this field explore 2D quantum materials that host multiferroic or concurrent ferroic and topological order. We present a computational discovery of multiferroic state with coexisting ferroelectric and ferromagnetic order in recently synthesized CH2OCH3-functionalized germanene. We show that an electric-field-induced rotation of the ligand CH2OCH3 molecule can serve as the driving mechanism to switch the electric polarization of the ligand molecule, while unpassivated Ge p(z) orbits generate ferromagnetism. Our study also reveals coexisting ferroelectric and topological order in ligand-functionalized arsenene, which possesses a switchable electric polarization and a Dirac transport channel. These findings offer insights into the fundamental physics underlying these coexisting quantum orders and open avenues for achieving states of matter with multiferroic or ferroic-topological order in 2D-layered materials for innovative memory or logic device implementations

Research on the Integral Practical and Aesthetic Design Teaching of Architecture and Site Environment —Taking Kindergarten Architecture and Site Logic Model Teaching Approach as an Example

The integral practical and aesthetic design teaching of architecture and site environment is expected to deal with the junior-grade design teaching in architecture major with a current situation that the insuffcient consideration of the site environment and the chaotic city image, which caused by long-term emphasis on single function and personality performance of architecture. The key to the integral practicability and aesthetics is the emphasis on the integrality of spatial logical order of those two factors, which contains the integral harmony of function attributes, scale, logics, and modal relationships and so on. Combine with the teaching of kindergarten architecture design, using architecture and site logic model teaching methodology, through the extraction cognitive teaching approach of the site environment order logics, the cognitive teaching approach of kindergarten architecture spatial logics, the strategic teaching approach of the congruent design of the integral order of architecture and site environment logics, module and model congruent counterpoint design teaching approach of architecture and large site environment order logics, organization and construction integrated design teaching approach of architecture and small site environment spatial logics, and result design teaching approach of architectures integrated into the landscape of large site environment and their surrounding small site environment and other teaching procedures to complete the teaching tasks of the integral practical and aesthetic design of kindergarten architecture and site environment.

Lysosomal acid lipase in mesenchymal stem cell stimulation of tumor growth and metastasis

Bone marrow mesenchymal stem cells (MSCs) are an important participant in the tumor microenvironment, in which they promote tumor growth and progression. Here we report for the first time that depletion of lysosomal acid lipase (LAL) in MSCs impairs their abilities to stimulate tumor growth and metastasis both in allogeneic and syngeneic mouse models. Reduced cell viability was observed in LAL-deficient (lal-/-) MSCs, which was a result of both increased apoptosis and decreased proliferation due to cell cycle arrest. The synthesis and secretion of cytokines and chemokines that are known to mediate MSCs' tumor-stimulating and immunosuppressive effects, i.e., IL-6, MCP-1 and IL-10, were down-regulated in lal-/- MSCs. When tumor cells were treated with the conditioned medium from lal-/- MSCs, decreased proliferation was observed, accompanied by reduced activation of oncogenic intracellular signaling molecules in tumor cells. Co-injection of lal-/- MSCs and B16 melanoma cells into wild type mice not only induced CD8+ cytotoxic T cells, but also decreased accumulation of tumor-promoting Ly6G+CD11b+ myeloid-derived suppressor cells (MDSCs), which may synergistically contribute to the impairment of tumor progression. Furthermore, lal-/- MSCs showed impaired differentiation towards tumor-associated fibroblasts. In addition, MDSCs facilitated MSC proliferation, which was mediated by MDSC-secreted cytokines and chemokines. Our results indicate that LAL plays a critical role in regulating MSCs' ability to stimulate tumor growth and metastasis, which provides a mechanistic basis for targeting LAL in MSCs to reduce the risk of cancer metastasis

Approximation and Generalization of DeepONets for Learning Operators Arising from a Class of Singularly Perturbed Problems

Singularly perturbed problems present inherent difficulty due to the presence of a thin boundary layer in its solution. To overcome this difficulty, we propose using deep operator networks (DeepONets), a method previously shown to be effective in approximating nonlinear operators between infinite-dimensional Banach spaces. In this paper, we demonstrate for the first time the application of DeepONets to one-dimensional singularly perturbed problems, achieving promising results that suggest their potential as a robust tool for solving this class of problems. We consider the convergence rate of the approximation error incurred by the operator networks in approximating the solution operator, and examine the generalization gap and empirical risk, all of which are shown to converge uniformly with respect to the perturbation parameter. By utilizing Shishkin mesh points as locations of the loss function, we conduct several numerical experiments that provide further support for the effectiveness of operator networks in capturing the singular boundary layer behavior

A Mechanism For Converting A Relational Database Into An Object-Oriented Model: An AIS Application

The object-oriented (OO) approach in system design and development is gaining popularity.  In the management information systems literature, OO system development is viewed as superior to conventional systems development because of advantages such as easier modeling, more efficient model reuse, and more convenient maintenance (Booch 1994; Briand, et al. 1999; Coleman, et al. 1994; Cockburn 1999).  Several studies have explored the applicability of the OO paradigm for the design and implementation of accounting information systems (AIS) and the advantages of OO design for this purpose (Adamson and Dilts 1995, Chu 1992a, 1992b; Kandelin and Lin 1992; Murthy and Wiggins 1993; Verdaasdonk 2003).  Nevertheless, OO techniques are often applied only to front-end applications while a relational database is generally used to store data at the back-end.  Based on an existing relational database model for a retail enterprise, this paper contributes to the AIS literature by providing a mechanism for transforming a relational database into an OO data model.

ReMasker: Imputing Tabular Data with Masked Autoencoding

We present ReMasker, a new method of imputing missing values in tabular data by extending the masked autoencoding framework. Compared with prior work, ReMasker is both simple -- besides the missing values (i.e., naturally masked), we randomly ``re-mask'' another set of values, optimize the autoencoder by reconstructing this re-masked set, and apply the trained model to predict the missing values; and effective -- with extensive evaluation on benchmark datasets, we show that ReMasker performs on par with or outperforms state-of-the-art methods in terms of both imputation fidelity and utility under various missingness settings, while its performance advantage often increases with the ratio of missing data. We further explore theoretical justification for its effectiveness, showing that ReMasker tends to learn missingness-invariant representations of tabular data. Our findings indicate that masked modeling represents a promising direction for further research on tabular data imputation. The code is publicly available